Centrifugal switch



Dec. 12, 1961 c. w. MERCHANT 3,013,132

CENTRIFUGAL SWITCH Filed May 2, 1960 INVENTOR.

44477197 506577044 yzs, flaw/5? United States Patent 3,013,132 CENTREFUGAL SWITCH Charles Wesley Merchant, Lake County, Ohio, assiguor to The Euclid Electric 8: Manufacturing Company, Madison, Ohio, a corporation of Ohio Filed May 2, 19%, Ser. No. 26,051 Claims. (Cl. 200-80) The present invention relates to an improved centrifugal switch control device for an apparatus connected thereto in which uniform or constant speed is required for the travel of its moving parts for the proper operation of such apparatus.

A principal object of the invention is to provide an electrical centrifugal switch control device that will break reduction or drop in the speed of travel of its moving parts.

, Still another object of the invention is to provide an electrical centrifugal switch control device that upon being connected to such apparatus will perform eiiiciently regardless of the position of its placement with respect to the axis of revolution of the governor member thereof.

Still another object of the invention is to provide an electrical centrifugal switch control device that will prevent damage to material being processed in an apparatus where a slowing down of the speed of such apparatus will result in an overexposure of such material caused by high temperature, or light, or a combination of both.

It is another object of the invention to provide an electrical centrifugal switch control device that is compact and has its member parts encased in a protective housing.

Other objects and advantages of the invention reside in a structure that is inexpensive to manufacture, has a minimum number of parts that are easy to assemble and install upon the mechanism or apparatus for which speed control is required and is efiicient in operation and maintenance.

Other objects and advantages more or less ancillary to the foregoing, and the manner in which all the various objects are realized will appear in the following description, which considered in connection with the accompanying drawings sets forth the preferred embodiment of the invention.

Referring to the drawings:

FIG. 1 is a side elevatioual view of the centrifugal switch control device shown largely in section and in which a portion of the casing of the micro switch is cut away to show the micro switch contacts;

FIG. 2 is a side elevational View of the said device in which a portion of the housing is cut away to show the governor weights in an extended position;

FIG. 3 is a perspective fragmentary view of a part of the governor assembly showing the weights and support disc attached thereto;

FIG. 4 is an end view of a part of the governor assembly showing the relative position of the weights and support disc in the governor assembly.

Referring particularly to the drawings, the improved centrifugal switch control device may preferably be made of suitable metal except for the non-conductor parts of the micro switch assembly and parts associated therewith which may preferably be made of hard rubber, phenolic or other insulating material.

-ter of said support disc 25 and is approximately the It consists of five principal parts, i.e. the outer protective housing It the inner rotating housing 11, the rotating governor assembly 12 contained within said inner housing 3.1, the actuator cup 13 and the micro switch assembly 14.

Referring to FIGS. 1 and 2 it will be seen that the outer protective housing 10 is cylindrical in form with one end 15 thereof open to receive the said inner housing 11 in axial alignment therewith and the micro switch assembly 14. The other end 16 is closed except for an integral axially aligned bearing support tube 17.

The said inner rotating housing 11 is cylindrical in form and also has one end 18 open to receive the governor assembly 12. The other end 19 thereof is closed with an axially aligned journal 20 integral therewith and which is seated in the bearing 21 mounted in the said bearing support tube 17.

The adjacent Walls of said housings 10 and 11 are spaced apart approximately the thickness of said bearing 21 to provide the free rotation of the said inner housing 11 within the said outer housing 10.

The remote end of said journal 20 has a power connection with the source of power (not shown) which comprises a keyed thrust collar 22 and a thrust collar inner housing pin 23 adjacent its said remote end and extending through said thrust collar 22 and journal 20. I

The said rotating governor assembly 12 is contained within said inner housing 11 and consists of weights 24, a beryllium copper resilient support disc 25, rivets 26, a guide pin 27, a compression coil spring 28 and a spring and actuator bearing 29.

The said weights 24 are preferably formed from a metallic cylinder which has a diameter slightly smaller than the corresponding diameter of the inner housing 11 and which has a bore 30 therethrough concentric with its cylindrical surface. The said metallic cylinder is cut longitudinally into preferably four radial sections of substantially equal weight and shape. On one end of each weight there is a blind hole 31 centered upon a radius that bisects the radial sides of each weight at the mid point between the surface of the said bore 30 and the cylindrical outer surface 32 thereof to receive rivets 26.

The said inner housing 11 has a groove 33 on its inner surface adjacent its open end 18 to receive said support disc 25.

The said support disc 25 has cars 34 projecting from its periphery that are seated in recesses 34a of the cylindrical wall of said inner housing 11 to maintain uniform rotation of the said disc with attached weights and the inner housing 11. The said support disc is held in place by a retaining ring 35 seated in the groove 33.

Said support disc 25 has apertures in the form of radial slots 36 forming inwardly directed radial spring leaves 37 of equal size whose radial edges are in the same plane as the radial surfaces of the said weight adjacent thereto. Each of said slots extends an equal distance from the cenlength of the radius of the cylinder from which are formed the weights. Each said spring leaf 37 is apertured at 38 on a radial bisector thereof and in alignment with said blind hole 31 to receive said rivets 26. The said weights 24 are attached to said support disc 25 by said rivets 26 with their cylindrical surfaces parallel to the inner wall of said inner housing 11 and are spaced apart at equal distances, one from the other, and from the inner wall and closed end of said inner housing 11.

The closed end 19 of the inner housing 11 has a blind hole 3? concentric with and extending into the journal 20 and in co-axial alignment therewith to fixedly receive said guide pin 27. The said guide pin 27 extends through said here 3i) and into a concentric blind hole 40 in the end 41 of the cylindrical body portion 42 of said spring and actuator bearing 29 and in co-axial alignment with said guide pin 27 and in slidable engagement therewith. The said compression coil spring 28 is mounted on said guide pin 27 and extends from the closed end 19 of the inner housing 11 through the bore St to a shoulder 43 adjacent the remote end 44 of the cylindrical body portion 42 of said spring and actuator bearing 29. The said spring and actuator bearing 29 is contained within the bore 30 With its said remote end 4t engaging the adjacent surface of the said spring leaves 37.

The said spring and actuator bearing 29* has an integral concentric pin 45 projecting through the support disc 25 at the inter-section of the radial slots 36 and into a concentric blind hole 46 of the cupped end 47 surface of the said cylindrical actuator cup 13 resting on the outer surface of said support disc 25. The said actuator cup 13 is preferably made of nylon.

The said micro switch assembly 14 is contained Within the outer housing adjacent the remote end 48 of the said actuator cup 13 and consists of a cylindrical switch mounting cap 49 and having a recess 50 in its inner end 51 to receive a micro switch 52'. Preferably said mounting cap is made of an insulating material with its cylindrical diameter equal to the inner diameter of the housing 10 and is fixedly mounted in the said open end thereof.

The said micro switch 52 is mounted in said recess 50 with the push button 53 thereof in coaxial alignment with the guide pin 27 and actuator bearing pin 45. The said push button 53 engaging and bearing upon the remote end 48 of the actuator cup 13 with suflicient pressure to open the switch contact points 54 while the weights 24 are at rest. The terminals 55 of said switch 52 project through apertures 56 in the base of the recess 50 of the actuator cup 13. The said terminals 55 provide a connection to the electrical control circuit (not shown) ofthe apparatus connected to said thrust collar 22.

The centrifugal switch control device may be mounted upon the apparatus connected thereto by the use of the well known attaching devices (not shown) such as a strap, clamp, flange or foot mounting.

An electrical circuit (not shown) including relay means is provided for starting the motor of such apparatus and bringing its moving parts up to the required speed prior to the closing of the micro switch 52.

It will be seen that the centrifugal switch control device may be connected to such apparatus requiring control in any suitable position without disturbing the efficiency of its operation due to gravity or movement of the said apparatus. The force exerted by the compression coil spring 28 together with the spring leaves 3-7 will resist the force of gravity upon the said weights 24 or any centrifugal force thereon, and retain the said weights 24 in parallel alignment with the axis of revolution until the critical control speed is reached. At this point the combined forces of the compression spring 28 and the spring leaves 37 are overcome, permitting the weights 24 to fly away from the axis of revolution to the extent permitted by the cylindrical wall of the said inner housing 11.

When the said weights 24 are in a said fly away position the said spring leaves 37 adjacent said actuator cup 13 and the said spring and actuator bearing 29 are depressed thereby disengaging the actuator cup 13 from the push button 53 of the micro switch 52. The release of the said push button 53 permits the contact points 54 of said micro switch 52 to close thereby closing the control circuit between said motor and the centrifugal control switch structure.

When the required speed of the moving parts has been attained and the said control circuit has been actuated, the said starting circuit to the motor is simultaneously broken and may not again be closed during such period of operation. T hus, a reduction of the speed of the moving parts of the apparatus, for any cause, Will also reduce the speed of revolution of the governor weights 24,

and should the said critical point be reached the forces exerted by the said compression spring 28 and the said spring disc will overcome the centrifugal force exerted by the said governor weights 24 and cause the said weights to retract to said parallel alignment and restore the said spring leaves 37 to a pressure position on the said actuator cup 13 and through it to a pressure position on the said push button 53 of the micro switch 52..

The said pressure on the said push button 53 opens the contact points 54 and breaks the control circuit to the motor of the apparatus and brings the moving parts of such apparatus to a stop.

For example, where it has been determined that the apparatus for which control is desired operates at its peak efficiency while the inner housing 11 is rotating approximately 500-525 r.p.m. then a compression coil spring 28 is provided that will deflect under the load created by the revolving weights 24 when the inner housing 11 reaches an ascending speed of 470-500 rpm. The said deflection allows the said weights 24 to fly away from the axis of revolution, thus removing the pressure on the push button 53 of the micro switch 52. When the said pressure is removed the switch contact points 54 close bringing the said control circuit into operation.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is understood that the specific terminology is not intended to be restrictive or confining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

What is claimed is:

1. A centrifugal switch; control device for an apparatus as described comprising a stationary cylindrical housing having one open end and an axially aligned journal bearing support tube extending through the closed end thereof, an inner cylindrical housing rotatably mounted therein in axial alignment therewith and spaced apart therefrom, and having one end open and an integral axially aligned journal on a closed end thereof mounted in said journal bearing, the said journal having apparatus connecting means adjacent the outer end thereof, governor control means mounted in said inner housing and secured thereto, said governor control means including a slotted support disc having inwardly directed radial spring leaves fixedly secured to the open end of said inner housing, governor weights mounted on said radial spring leaves, compression spring means abutting the closed end of said inner housing and engaging said support disc, an actuator cup mounted on said governor control means in axial alignment therewith and resting on said radial spring leaves, a switch mounting cap disposed in said open end of said stationary housing, an electrical micro switch fixedly mounted thereon, said micro switch having a switch push button slideably engaging said actuator cup and in axial alignment therewith and terminals for electrical control circuit connection therewith.

2. A centrifugal switch control device for an apparatus as described comprising a stationary cylindrical housing having one open end and an axially aligned journal bearing support tube extending through the closed end thereof, an inner cylindrical housing rotatably mounted therein in axial alignment therewith and spaced apart therefrom, and having one end open and an integral axially aligned journal on a closed end thereof mounted in said journal bearing, the said journal having apparatus connecting means adjacent the outer end thereof, governor control means mounted in said inner housing and secured thereto, said governor control means including a slotted support disc having inwardly directed radial spring leaves fixedly secured to the open end of said inner housing, governor weights mounted on said radial spring leaves, a compression coil spring mounted on an axial aligned guide pin in the closed end of said inner housing, the said compression coil spring abutting the closed end of said inner housing and engaging an actuator and spring bearing adjacent said support disc, an actuator cup mounted on said actuator and spring bearing in axial alignment therewith, and resting on said radial spring leaves, a switch mounting cap disposed in the said open end of said stationary housing, an electrical micro switch fixedly mounted thereon, said micro switch having a switch push button slideably engaging said actuator cup and in axial alignment therewith and terminals for electrical control circuit connection therewith.

3. A centrifugal switch control device for an apparatus as described comprising a stationary cylindrical housing having one open end and an axially aligned journal bearing support tube extending through the closed end thereof, an inner cylindrical housing rotatably mounted therein in axial alignment therewith and spaced apart there from, and having one open end and an integral axially aligned journal on a closed end thereof mounted in said journal bearing, the said journal having apparatus connecting means adjacent the outer end thereof, governor control means mounted in said inner housing and secured thereto, said governor control means including a support disc having internal radial slots with the peripheral edge thereof fixedly secured to the open end of said inner housing, governor weights mounted on said support disc, and compression spring means abutting the closed end of said inner housing and engaging said support disc, an actuator cup mounted on said governor control means and in axial alignment therewith, a switch mounting cap disposed in said stationary housing, an electrical micro switch fixedly mounted thereon, said micro switch having a switch push button slideably engaging said actuator cup and in axial alignment therewith and terminals for electrical control circuit connection therewith.

4. A centrifugal switch control device for an apparatus as described comprising a stationary cylindrical housing having one open end and an axially aligned journal bearing support tube extending through the closed end thereof, an inner cylindrical housing rotatably mounted therein in axial alignment therewith and spaced apart therefrom, and having one open end and an integral axially aligned journal on a closed end thereof mounted in said journal bearing, the said journal having apparatus connecting means adjacent the outer end thereof, governor control means mounted in said inner housing and secured thereto, said governor control means including a support disc with internal slots forming radial spring leaves, the peripheral edge of said support disc fixedly secured to the open end of said inner housing, governor weights having the bases thereof mounted on said radial spring leaves and compression spring means abutting the closed end of said inner housing and engaging said radial spring leaves, and actuator cup mounted on said governor control means and resting on said spring leaves and in axial alignment therewith, a switch mounting cap disposed in said stationary housing, an electrical micro switch fixedly mounted thereon, said micro switch having a switch push button slideably engaging said actuator cup and in axial alignment therewith and terminals for electrical control circuit connection therewith.

5. A centrifugal switch control device for an apparatus as described comprising a stationary cylindrical housing having one open end and an axially aligned journal bearing support tube extending through the closed end thereof, an inner cylindrical housing rotatably mounted therein in axial alignment therewith and spaced apart therefrom, and having one end open and an integral axially aligned journal on a closed end thereof mounted in said journal bearing, the said journal having apparatus connecting means adjacent the outer end thereof, governor control means mounted in said inner housing and secured thereto, said governor control means including a slotted support disc having inwardly directed radial spring leaves, the peripheral edge of said support disc fixedly secured to the open end of said inner housing, governor weights forming cylindrical sectors having the bases thereof mounted on said radial spring leaves, a compression coil spring mounted on an axial aligned guide pin in the closed end of said inner housing, the said compression coil spring abutting the closed end of said inner housing and engaging an actuator and spring bearing adjacent said radial spring leaves, a pin on the remote end of said actuator and spring bearing extending through said support disc in axial alignment therewith, an actuator cup mounted on said remote end pin and resting on the outer surface of said radial spring leaves, a switch mounting cap disposed in the said open end of said stationary housing, an electrical micro switch fixedly mounted thereon, said micro switch having a switch push button slideably engaging said actuator cup and in axial alignment therewith and terminals for electrical control circuit connection therewith.

References Cited in the file of this patent UNITED STATES PATENTS 

